Database upgrading, revision 1.

openlp/core/lib/db.py

@@ -31,9 +31,9 @@ import logging
 import os
 
 from PyQt4 import QtCore
-from sqlalchemy import create_engine, MetaData
+from sqlalchemy import Table, MetaData, Column, types, create_engine
 from sqlalchemy.exc import InvalidRequestError
-from sqlalchemy.orm import scoped_session, sessionmaker
+from sqlalchemy.orm import scoped_session, sessionmaker, mapper
 from sqlalchemy.pool import NullPool
 
 from openlp.core.utils import AppLocation, delete_file
@@ -59,6 +59,42 @@ def init_db(url, auto_flush=True, auto_commit=False):
         autocommit=auto_commit, bind=engine))
     return session, metadata
 
+
+def upgrade_db(url, upgrade):
+    """
+    Upgrade a database.
+
+    ``url``
+        The url of the database to upgrade.
+
+    ``upgrade``
+        The python module that contains the upgrade instructions.
+    """
+    session, metadata = init_db(url)
+    tables = upgrade.upgrade_setup(metadata)
+    metadata_table = Table(u'metadata', metadata,
+        Column(u'key', types.Unicode(64), primary_key=True),
+        Column(u'value', types.UnicodeText(), default=None)
+    )
+    metadata_table.create(checkfirst=True)
+    mapper(Metadata, metadata_table)
+    version_meta = session.query(Metadata).get(u'version')
+    if version_meta is None:
+        version_meta = Metadata.populate(key=u'version', value=u'0')
+        version = 0
+    else:
+        version = int(version_meta.value)
+    version += 1
+    while hasattr(upgrade, u'upgrade_%d' % version):
+        log.debug(u'Running upgrade_%d', version)
+        do_upgrade = getattr(upgrade, u'upgrade_%d' % version)
+        if not do_upgrade(session, metadata, tables):
+            break
+        version += 1
+        version_meta.value = unicode(version)
+    session.add(version_meta)
+    session.commit()
+
 def delete_database(plugin_name, db_file_name=None):
     """
     Remove a database file from the system.
@@ -79,6 +115,7 @@ def delete_database(plugin_name, db_file_name=None):
             AppLocation.get_section_data_path(plugin_name), plugin_name)
     return delete_file(db_file_path)
 
+
 class BaseModel(object):
     """
     BaseModel provides a base object with a set of generic functions
@@ -94,11 +131,18 @@ class BaseModel(object):
         return instance
 
 
+class Metadata(BaseModel):
+    """
+    Provides a class for the metadata table.
+    """
+    pass
+
+
 class Manager(object):
     """
     Provide generic object persistence management
     """
-    def __init__(self, plugin_name, init_schema, db_file_name=None):
+    def __init__(self, plugin_name, init_schema, db_file_name=None, upgrade_schema=None):
         """
         Runs the initialisation process that includes creating the connection
         to the database and the tables if they don't exist.
@@ -109,6 +153,9 @@ class Manager(object):
         ``init_schema``
             The init_schema function for this database
 
+        ``upgrade_schema``
+            The upgrade_schema function for this database
+
         ``db_file_name``
             The file name to use for this database. Defaults to None resulting
             in the plugin_name being used.
@@ -134,6 +181,8 @@ class Manager(object):
                 unicode(settings.value(u'db hostname').toString()),
                 unicode(settings.value(u'db database').toString()))
         settings.endGroup()
+        if upgrade_schema:
+            upgrade_schema(self.db_url)
         self.session = init_schema(self.db_url)
 
     def save_object(self, object_instance, commit=True):

openlp/plugins/songs/lib/db.py

@@ -32,7 +32,8 @@ the Songs plugin
 from sqlalchemy import Column, ForeignKey, Table, types
 from sqlalchemy.orm import mapper, relation
 
-from openlp.core.lib.db import BaseModel, init_db
+from openlp.core.lib.db import BaseModel, init_db, upgrade_db
+from openlp.plugins.songs.lib import upgrade
 
 class Author(BaseModel):
     """
@@ -70,6 +71,14 @@ class Topic(BaseModel):
     """
     pass
 
+def upgrade_schema(url):
+    """
+    Upgrades the songs database.
+
+    ``url``
+        The database to upgrade
+    """
+    upgrade_db(url, upgrade)
 
 def init_schema(url):
     """
@@ -111,10 +120,6 @@ def init_schema(url):
         * file_name
         * type
 
-    **media_files_songs Table**
-        * media_file_id
-        * song_id
-
     **song_books Table**
         The *song_books* table holds a list of books that a congregation gets
         their songs from, or old hymnals now no longer used. This table has the
@@ -162,7 +167,7 @@ def init_schema(url):
 
     # Definition of the "authors" table
     authors_table = Table(u'authors', metadata,
-        Column(u'id', types.Integer, primary_key=True),
+        Column(u'id', types.Integer(), primary_key=True),
         Column(u'first_name', types.Unicode(128)),
         Column(u'last_name', types.Unicode(128)),
         Column(u'display_name', types.Unicode(255), index=True, nullable=False)
@@ -170,22 +175,25 @@ def init_schema(url):
 
     # Definition of the "media_files" table
     media_files_table = Table(u'media_files', metadata,
-        Column(u'id', types.Integer, primary_key=True),
+        Column(u'id', types.Integer(), primary_key=True),
+        Column(u'song_id', types.Integer(), ForeignKey(u'songs.id'),
+            default=None),
         Column(u'file_name', types.Unicode(255), nullable=False),
-        Column(u'type', types.Unicode(64), nullable=False, default=u'audio')
+        Column(u'type', types.Unicode(64), nullable=False, default=u'audio'),
+        Column(u'weight', types.Integer(), default=0)
     )
 
     # Definition of the "song_books" table
     song_books_table = Table(u'song_books', metadata,
-        Column(u'id', types.Integer, primary_key=True),
+        Column(u'id', types.Integer(), primary_key=True),
         Column(u'name', types.Unicode(128), nullable=False),
         Column(u'publisher', types.Unicode(128))
     )
 
     # Definition of the "songs" table
     songs_table = Table(u'songs', metadata,
-        Column(u'id', types.Integer, primary_key=True),
+        Column(u'id', types.Integer(), primary_key=True),
-        Column(u'song_book_id', types.Integer,
+        Column(u'song_book_id', types.Integer(),
             ForeignKey(u'song_books.id'), default=None),
         Column(u'title', types.Unicode(255), nullable=False),
         Column(u'alternate_title', types.Unicode(255)),
@@ -202,31 +210,23 @@ def init_schema(url):
 
     # Definition of the "topics" table
     topics_table = Table(u'topics', metadata,
-        Column(u'id', types.Integer, primary_key=True),
+        Column(u'id', types.Integer(), primary_key=True),
         Column(u'name', types.Unicode(128), index=True, nullable=False)
     )
 
     # Definition of the "authors_songs" table
     authors_songs_table = Table(u'authors_songs', metadata,
-        Column(u'author_id', types.Integer,
+        Column(u'author_id', types.Integer(),
             ForeignKey(u'authors.id'), primary_key=True),
-        Column(u'song_id', types.Integer,
+        Column(u'song_id', types.Integer(),
-            ForeignKey(u'songs.id'), primary_key=True)
-    )
-
-    # Definition of the "media_files_songs" table
-    media_files_songs_table = Table(u'media_files_songs', metadata,
-        Column(u'media_file_id', types.Integer,
-            ForeignKey(u'media_files.id'), primary_key=True),
-        Column(u'song_id', types.Integer,
             ForeignKey(u'songs.id'), primary_key=True)
     )
 
     # Definition of the "songs_topics" table
     songs_topics_table = Table(u'songs_topics', metadata,
-        Column(u'song_id', types.Integer,
+        Column(u'song_id', types.Integer(),
             ForeignKey(u'songs.id'), primary_key=True),
-        Column(u'topic_id', types.Integer,
+        Column(u'topic_id', types.Integer(),
             ForeignKey(u'topics.id'), primary_key=True)
     )
 
@@ -238,8 +238,7 @@ def init_schema(url):
             'authors': relation(Author, backref='songs',
                 secondary=authors_songs_table, lazy=False),
             'book': relation(Book, backref='songs'),
-            'media_files': relation(MediaFile, backref='songs',
+            'media_files': relation(MediaFile, backref='songs'),
-                secondary=media_files_songs_table),
             'topics': relation(Topic, backref='songs',
                 secondary=songs_topics_table)
         })

openlp/plugins/songs/lib/upgrade.py

@@ -0,0 +1,63 @@
+# -*- coding: utf-8 -*-
+# vim: autoindent shiftwidth=4 expandtab textwidth=80 tabstop=4 softtabstop=4
+
+###############################################################################
+# OpenLP - Open Source Lyrics Projection                                      #
+# --------------------------------------------------------------------------- #
+# Copyright (c) 2008-2011 Raoul Snyman                                        #
+# Portions copyright (c) 2008-2011 Tim Bentley, Gerald Britton, Jonathan      #
+# Corwin, Michael Gorven, Scott Guerrieri, Matthias Hub, Meinert Jordan,      #
+# Armin Köhler, Joshua Miller, Stevan Pettit, Andreas Preikschat, Mattias     #
+# Põldaru, Christian Richter, Philip Ridout, Simon Scudder, Jeffrey Smith,    #
+# Maikel Stuivenberg, Martin Thompson, Jon Tibble, Frode Woldsund             #
+# --------------------------------------------------------------------------- #
+# This program is free software; you can redistribute it and/or modify it     #
+# under the terms of the GNU General Public License as published by the Free  #
+# Software Foundation; version 2 of the License.                              #
+#                                                                             #
+# This program is distributed in the hope that it will be useful, but WITHOUT #
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or       #
+# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for    #
+# more details.                                                               #
+#                                                                             #
+# You should have received a copy of the GNU General Public License along     #
+# with this program; if not, write to the Free Software Foundation, Inc., 59  #
+# Temple Place, Suite 330, Boston, MA 02111-1307 USA                          #
+###############################################################################
+"""
+The :mod:`upgrade` module provides a way for the database and schema that is the backend for
+the Songs plugin
+"""
+
+from sqlalchemy import Column, ForeignKey, Table, types
+from migrate import changeset
+from migrate.changeset.constraint import ForeignKeyConstraint
+
+def upgrade_setup(metadata):
+    """
+    Set up the latest revision all tables, with reflection, needed for the
+    upgrade process. If you want to drop a table, you need to remove it from
+    here, and add it to your upgrade function.
+    """
+    tables = {
+        u'authors': Table(u'authors', metadata, autoload=True),
+        u'media_files': Table(u'media_files', metadata, autoload=True),
+        u'song_books': Table(u'song_books', metadata, autoload=True),
+        u'songs': Table(u'songs', metadata, autoload=True),
+        u'topics': Table(u'topics', metadata, autoload=True),
+        u'authors_songs': Table(u'authors_songs', metadata, autoload=True),
+        u'songs_topics': Table(u'songs_topics', metadata, autoload=True)
+    }
+    return tables
+
+
+def upgrade_1(session, metadata, tables):
+    Table(u'media_files_songs', metadata, autoload=True).drop(checkfirst=True)
+    Column(u'song_id', types.Integer(), default=None)\
+        .create(table=tables[u'media_files'], populate_default=True)
+    Column(u'weight', types.Integer(), default=0)\
+        .create(table=tables[u'media_files'], populate_default=True)
+    if metadata.bind.url.get_dialect().name != 'sqlite':
+        ForeignKeyConstraint([u'song_id'], [u'songs.id'],
+            table=tables[u'media_files']).create()
+    return True

openlp/plugins/songs/songsplugin.py

@@ -37,7 +37,7 @@ from openlp.core.lib.db import Manager
 from openlp.core.lib.ui import UiStrings, base_action, icon_action
 from openlp.core.utils.actions import ActionList
 from openlp.plugins.songs.lib import clean_song, SongMediaItem, SongsTab
-from openlp.plugins.songs.lib.db import init_schema, Song
+from openlp.plugins.songs.lib.db import init_schema, upgrade_schema, Song
 from openlp.plugins.songs.lib.importer import SongFormat
 from openlp.plugins.songs.lib.olpimport import OpenLPSongImport
 
@@ -58,8 +58,8 @@ class SongsPlugin(Plugin):
         Create and set up the Songs plugin.
         """
         Plugin.__init__(self, u'songs', plugin_helpers, SongMediaItem, SongsTab)
+        self.manager = Manager(u'songs', init_schema, upgrade_schema=upgrade_schema)
         self.weight = -10
-        self.manager = Manager(u'songs', init_schema)
         self.icon_path = u':/plugins/plugin_songs.png'
         self.icon = build_icon(self.icon_path)